Clutch and operating device



April 21, 1931.

J. T. DICKSON CLUTCH AND OPERATING DEVICE Filed June 19, 1928 I lll fmre/zfar.

Patented Apr. 21, 1931 name '1. DIGKBQN, LOS ANGELES, CALIFORNIA CLUTCH AND OPERATING DEVICE Application mm June-19, ms. Serial No. seam.

The present invention relatesto clutches and clutch operating devices .of the type described in my- Patent No. 1,618,644

One of the objects of this invent on is to provide an automatic tor u e' regulating clutch operatin device w ch may adapted to a wi e variety of common types of clutches to attain all the advantages peculiar to the clutch described in the aforesaid patent.

- Anotherobject of the invention is to provide a simple and complete clutch and'pulr ley attachment for common typesof electric motors; thereby providing a complete power 1 unit in which theload is taken by the motor only when the motor has had ample time to reach full speed andwhereby the load is released when it becomes excessive.

Many other objects and advantages of my 0 invention will appear hereinafter.

I have illustrated by the accompanying drawings one practical embodiment of my invention.

In the said drawings:

Figure 1 is a view in vertical section and elevation of the said embodiment.

Figure 2 is a view in end elevation thereof, the view showing parts broken away to reveal underlying parts hereinafter known as the weights and spider respectively.

More specifically, in carrying out my invention in the present embodiment I rovide an extension shaft 5 adapted to be tted to a common motor shaft 6 such as found on the motor 7 The extension shaft is accordingly provided with an enlarged portion 5w provided with a socket 5b in which the shaft 6 of the motor is inserted with a press fit or key (not shown) to cause the extension shaft to revolve positively with the motor shaft.

Integral with the extension shaft there is provided a driving member or clutch disc 8 carrying a suitable clutch facing 9 composed 4 of cork, brake lining or the like.

5a of the motor shaft 5 I have provided a common wood pulley 10; the pulley being fitted with an attached driven member or clutch disc 11. It will beapparent now that the pulley under load may remain mo- Loosely mounted around the larger part tionless on the shaft while the motor re- I theshaft into contact with the drivin membe ber, then the motor would be frictionally connectedto the pulley thru the friction facing 9. In order to automatically engage anddisen age the clutch discs as required I provide t e operating mechanism which I will now describe. The said operating mechanism consists primarily of two similar cupped discs 12, 12, the weights 13, 13 and the thrust bearings 14 and 15 respectively.

The thrust bearings are of a common commercial type each fitted closely around a corresponding annular extension 12a of the corresponding member 12. The cupped members are loosely fitted on the shaft 5. The cupped discs are juxtaposed on the shaft with their open sides toward each other so that they enclose a space 16. One thrust bearing, which is adapted to carry both radial and end thrust, is disposed between the pulley andthe corresponding adjacent cupped member 12, while the other bearing is positioned adjacent the other cupped member and between it and an end collar 17 which is held by a nut 18 threaded to the shaft 5. r

The space 16 is of decreasing laterally measured width by reasonof the members 12 providing opposed faces 19 converging radially outwardly. In the space 16 are positioned suitable weights arran ed to be moved radially outward by centri ugal force to spread the members 12, 12 apart axially of the shaft. These weights have correspondingly tapered outer surfaces 20 contiguous to the faces 19 and the angle of the faces 19 is predetermined so that with a given rotative speed the weights will move said members 12, 12 apart with a given thrust.

While the weights are loosely containedin the space 16 so as to be movable freely? radially and even circumferentially if required, they are held in circumferentially spaced relation to each other by the spider, which also serves to hold the weights in correct transverse position so that they do not become tilted from the horizontal. For such urpose the spider is provided with radial notches 22, and each weight is of spool shape and fitted loosely in the corres onding notch.

nsidering the operation of the complete unit; When the motor is at rest the parts assume the position shown; that is to say, all parts tend to assume a position where the clutch discs are not in actual contact and where the members 12, 12 are not imposing any thrust on the bearings or upon the ulley and clutch discs. The lowermost o the weights is in slight frictional contact with both faces 19 and is held there by gravity, thus acting to hold the members 12, 12 apart sufiiciently to take up lost motion adjacent the bearings but not necessarily sufficient to hold the riven disc in contact with the driving disc.

Wit the parts in the position shown the motor is started, and like all electric motors starting without load will quickly attain full speed. Owing to the slight avity-imposed frictional contact of the mem ers 12, 12 with the shaft 5, the members eventually reach a rotative speed approximate to that of the motor but of course at a delayed or retarded rate.

As the weights attain a given speed they fly outward radially and act on the faces 19 to force the members 12, 12 apart, these members acting thru the thrust bearin as explained to force the pulley axially o the shaft a slight distance and so force the driven disc into frictional contact with the driving disc so that the pulley is driven by the motor. In m improved clutch the operatin device, w ich is loose with regard to bot the driving and driven members, is slowl and constantly accelerated whether or not tile discs are in engagement, and first slight contact of one disc with the other would in no way either appreciably retard or accelerate the centrifu al weights, particularl because of the riction reducing thrust arin s and the otherwise indirect connection 0 the operating device to the other rotating parts.

Accordingly the motor is slowly and gradually connected with the load and the motor is never overloaded nor is the load imposed until the motor has settled down to full speed, after startin When the torque becomes excessive the c utch will slip since the thrust is limited by centrifugal force and is arranged and predetermined so that the motor can not overload. Should the motor tend to lag for any reason, the clutch will fully or partially release as the case may be to assist the motor back to normal speed.

The construction shown is by way of example and does not limit the scope of the invention, any construction co within the scope of the a pended claim being permissible without eparting from the spirit of my invention. I

I claim:

An attachment of the class described oomprisin an extension shaft having a portion of en arged diameter to befitted over a motor shaft and a portion of reduced diameter to extend co-axiallybeyond said motor shaft, a driving disc on said extension shaft, adjacent the portion of larger diameter, a pu ley loosely encompassin the portion of ar er diameter, a driven d iec fixed to said pu ey adjacent the driving disc, said pulley with its driven disc and said driving disc being relatively movable axially of the shaft for frictional drivi -and-dr1ven engagement, and centrifuga y effected 0 rating means for so moving said pulley an dri member; said means comprising a paii' i axially movable discs loosely encom assing the portion of lesser diameter of sai extension shaft, .a thrust bearing between said pulley and the ad'acent one of said axiall movable discs, a t rust collar on said sha adjacent the other of said axially movable discs, a second thrust bearing between said last mentioned disc and said collar; said axially movable discs resentin inside faces converging radially rom sai shaft, and weights acting on said surfaces and dis between said discs and movable radial y by centrifugal force.

JAMES T. DICKSON.

Ill 

